A new study suggests that when humans are awake after midnight, neurophysiological changes in the brain lead to more negative outcomes.
The researchers of the hypothesis, which was published in the journal Frontiers in Network Psychology in March, are calling for new studies on the human brain after they discovered evidence that when humans are awake during the biological circadian night, neurophysiological changes in the brain causes them to view the world negatively, engage in harmful behaviors and make impulsive decisions.
The study, “The Mind After Midnight: Nocturnal Wakefulness, Behavioral Dysregulation, and Psychopathology,” suggests that the brain is not meant to be awake after midnight as the resulting impulsive decisions are likely to lead to addictive behaviors, including overeating, drinking, gambling or criminal activity, without thinking through the consequences. The changes also cause people to see the world more negatively than they typically do during the day.
“The basic idea is that from a high level, global, evolutionary standpoint, your internal biological circadian clock is tuned towards processes that promote sleep, not wakefulness, after midnight,” Elizabeth B. Klerman, MD, PhD, the senior author of the study, reportedly said.
Klerman is also an investigator in the Department of Neurology at Massachusetts General Hospital and a professor of neurology at Harvard Medical School.
She explained that our circadian rhythms change over the course of a 24-hour day. The “positive affect” is higher during the day, when an individual’s circadian clock is tuned for wakefulness. On the other hand, the “negative affect” rises to a high point at night.
The authors noted that incidents of suicide, violent crimes and drug use are more statistically common at night. Human bodies also naturally produce more dopamine at night, which can change one’s reward and motivation system, increasing the likelihood of risky behaviors.
In a 2019 study published in the journal Sleep Medicine, researchers from Flinders University, University of Helsinki and the Finnish company Polar found that young and middle-aged adults in Asia get the least sleep or have the shortest sleep duration.
The study explored the sleeping habits of 17,335 people aged 16 to 30. Researchers required participants to wear fitness trackers in order to measure their 14-day sleep patterns.
The findings suggest that people in Asia likely get less sleep due to cultural factors and societal functions.
“Higher work and educational demands in Asian countries compared to the west likely explain the later shorter sleep duration, coupled with similar catch up sleep, seen in those Asian regions,” sleep expert Professor Michael Gradisar said.
The authors of the “Mind After Midnight” hypothesis suggested that understanding how the brain changes at night may lead to better strategies in combating crimes and preventing substance abuse and suicides.
“There are millions of people who are awake in the middle of the night, and there’s fairly good evidence that their brain is not functioning as well as it does during the day,” Klerman said. “My plea is for more research to look at that, because their health and safety, as well as that of others, is affected.”